This study provided a systematic review of the ecological issues arising from the development of saline-alkali land in China. These included secondary salinization, the formation of groundwater depression cones, wetland shrinkage and functional degradation, and reduction in natural vegetation, as well as high remediation costs and pollution risks. In addition, it clarified the technological development pathways for the comprehensive utilization of saline-alkali land. These pathways encompassed four major directions: targeted strategies under a systematic management approach, cost-effective remediation under new ecological requirements, dual-force development through land-crop synergy, and specialized agriculture aligned with the broader concept of food. Furthermore, the study proposed an integrated strategy to strengthen the comprehensive management of saline-alkali lands, including emphasizing zonal rehabilitation of saline-alkali farmland, establishing a collaborative innovation system, and advancing fundamental theories and key technologies for sustainable utilization. It also recommended developing a tiered land-use model to support pilot programs for reserve resources and cultivated land, promoting specialized agriculture, enhancing productive capacity, advancing water-adapted planting, fostering innovation in water-saving agricultural technology, and strengthening ecological monitoring and impact assessment. This study provided the theoretical foundation and strategic support for ecological protection in the comprehensive utilization of saline-alkali land in China.

Water-saving rice systems must maintain yield targets while reducing water consumption. Applying biodegradable film to cover the soil surface reduces water loss through evapotranspiration, establishing a warmer, more humid microenvironment for rice growth compared to traditional paddy rice systems. This study examined soil water regimes for rice production in Northeast China, comparing rice growth with and without biodegradable mulch film under continuous flooding, drip irrigation, and controlled irrigation conditions. The implementation of biodegradable mulch film elevated soil temperature and sustained soil moisture during early rice development. Continuous flooding with biodegradable mulch film yielded the highest rice production (9.4 Mg ha^–1) and net profit of approximately 11,800 CNY ha^–1. Drip irrigation with biodegradable mulch film achieved maximum water efficiency, demonstrating the highest water productivity (1.25 kg m^–3) and minimum water consumption (235 mm). Root length, weight, and surface area in the 0–40 cm soil layer exhibited positive correlations with water productivity, shoot dry matter, and yield, indicating that root morphological characteristics, particularly during the panicle initiation stage, enhanced rice production and water conservation. The findings demonstrate that biodegradable mulch film created favorable soil conditions for root proliferation, enabling higher yields in water-saving rice systems.